xref: /linux/net/ipv4/ipconfig.c (revision b24413180f5600bcb3bb70fbed5cf186b60864bd)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Automatic Configuration of IP -- use DHCP, BOOTP, RARP, or
4  *  user-supplied information to configure own IP address and routes.
5  *
6  *  Copyright (C) 1996-1998 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
7  *
8  *  Derived from network configuration code in fs/nfs/nfsroot.c,
9  *  originally Copyright (C) 1995, 1996 Gero Kuhlmann and me.
10  *
11  *  BOOTP rewritten to construct and analyse packets itself instead
12  *  of misusing the IP layer. num_bugs_causing_wrong_arp_replies--;
13  *					     -- MJ, December 1998
14  *
15  *  Fixed ip_auto_config_setup calling at startup in the new "Linker Magic"
16  *  initialization scheme.
17  *	- Arnaldo Carvalho de Melo <acme@conectiva.com.br>, 08/11/1999
18  *
19  *  DHCP support added.  To users this looks like a whole separate
20  *  protocol, but we know it's just a bag on the side of BOOTP.
21  *		-- Chip Salzenberg <chip@valinux.com>, May 2000
22  *
23  *  Ported DHCP support from 2.2.16 to 2.4.0-test4
24  *              -- Eric Biederman <ebiederman@lnxi.com>, 30 Aug 2000
25  *
26  *  Merged changes from 2.2.19 into 2.4.3
27  *              -- Eric Biederman <ebiederman@lnxi.com>, 22 April Aug 2001
28  *
29  *  Multiple Nameservers in /proc/net/pnp
30  *              --  Josef Siemes <jsiemes@web.de>, Aug 2002
31  */
32 
33 #include <linux/types.h>
34 #include <linux/string.h>
35 #include <linux/kernel.h>
36 #include <linux/jiffies.h>
37 #include <linux/random.h>
38 #include <linux/init.h>
39 #include <linux/utsname.h>
40 #include <linux/in.h>
41 #include <linux/if.h>
42 #include <linux/inet.h>
43 #include <linux/inetdevice.h>
44 #include <linux/netdevice.h>
45 #include <linux/if_arp.h>
46 #include <linux/skbuff.h>
47 #include <linux/ip.h>
48 #include <linux/socket.h>
49 #include <linux/route.h>
50 #include <linux/udp.h>
51 #include <linux/proc_fs.h>
52 #include <linux/seq_file.h>
53 #include <linux/major.h>
54 #include <linux/root_dev.h>
55 #include <linux/delay.h>
56 #include <linux/nfs_fs.h>
57 #include <linux/slab.h>
58 #include <linux/export.h>
59 #include <net/net_namespace.h>
60 #include <net/arp.h>
61 #include <net/dsa.h>
62 #include <net/ip.h>
63 #include <net/ipconfig.h>
64 #include <net/route.h>
65 
66 #include <linux/uaccess.h>
67 #include <net/checksum.h>
68 #include <asm/processor.h>
69 
70 #if defined(CONFIG_IP_PNP_DHCP)
71 #define IPCONFIG_DHCP
72 #endif
73 #if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP)
74 #define IPCONFIG_BOOTP
75 #endif
76 #if defined(CONFIG_IP_PNP_RARP)
77 #define IPCONFIG_RARP
78 #endif
79 #if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP)
80 #define IPCONFIG_DYNAMIC
81 #endif
82 
83 /* Define the friendly delay before and after opening net devices */
84 #define CONF_POST_OPEN		10	/* After opening: 10 msecs */
85 #define CONF_CARRIER_TIMEOUT	120000	/* Wait for carrier timeout */
86 
87 /* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
88 #define CONF_OPEN_RETRIES 	2	/* (Re)open devices twice */
89 #define CONF_SEND_RETRIES 	6	/* Send six requests per open */
90 #define CONF_BASE_TIMEOUT	(HZ*2)	/* Initial timeout: 2 seconds */
91 #define CONF_TIMEOUT_RANDOM	(HZ)	/* Maximum amount of randomization */
92 #define CONF_TIMEOUT_MULT	*7/4	/* Rate of timeout growth */
93 #define CONF_TIMEOUT_MAX	(HZ*30)	/* Maximum allowed timeout */
94 #define CONF_NAMESERVERS_MAX   3       /* Maximum number of nameservers
95 					   - '3' from resolv.h */
96 
97 #define NONE cpu_to_be32(INADDR_NONE)
98 #define ANY cpu_to_be32(INADDR_ANY)
99 
100 /*
101  * Public IP configuration
102  */
103 
104 /* This is used by platforms which might be able to set the ipconfig
105  * variables using firmware environment vars.  If this is set, it will
106  * ignore such firmware variables.
107  */
108 int ic_set_manually __initdata = 0;		/* IPconfig parameters set manually */
109 
110 static int ic_enable __initdata;		/* IP config enabled? */
111 
112 /* Protocol choice */
113 int ic_proto_enabled __initdata = 0
114 #ifdef IPCONFIG_BOOTP
115 			| IC_BOOTP
116 #endif
117 #ifdef CONFIG_IP_PNP_DHCP
118 			| IC_USE_DHCP
119 #endif
120 #ifdef IPCONFIG_RARP
121 			| IC_RARP
122 #endif
123 			;
124 
125 static int ic_host_name_set __initdata;	/* Host name set by us? */
126 
127 __be32 ic_myaddr = NONE;		/* My IP address */
128 static __be32 ic_netmask = NONE;	/* Netmask for local subnet */
129 __be32 ic_gateway = NONE;	/* Gateway IP address */
130 
131 #ifdef IPCONFIG_DYNAMIC
132 static __be32 ic_addrservaddr = NONE;	/* IP Address of the IP addresses'server */
133 #endif
134 
135 __be32 ic_servaddr = NONE;	/* Boot server IP address */
136 
137 __be32 root_server_addr = NONE;	/* Address of NFS server */
138 u8 root_server_path[256] = { 0, };	/* Path to mount as root */
139 
140 /* vendor class identifier */
141 static char vendor_class_identifier[253] __initdata;
142 
143 #if defined(CONFIG_IP_PNP_DHCP)
144 static char dhcp_client_identifier[253] __initdata;
145 #endif
146 
147 /* Persistent data: */
148 
149 #ifdef IPCONFIG_DYNAMIC
150 static int ic_proto_used;			/* Protocol used, if any */
151 #else
152 #define ic_proto_used 0
153 #endif
154 static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
155 static u8 ic_domain[64];		/* DNS (not NIS) domain name */
156 
157 /*
158  * Private state.
159  */
160 
161 /* Name of user-selected boot device */
162 static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
163 
164 /* Protocols supported by available interfaces */
165 static int ic_proto_have_if __initdata;
166 
167 /* MTU for boot device */
168 static int ic_dev_mtu __initdata;
169 
170 #ifdef IPCONFIG_DYNAMIC
171 static DEFINE_SPINLOCK(ic_recv_lock);
172 static volatile int ic_got_reply __initdata;    /* Proto(s) that replied */
173 #endif
174 #ifdef IPCONFIG_DHCP
175 static int ic_dhcp_msgtype __initdata;	/* DHCP msg type received */
176 #endif
177 
178 
179 /*
180  *	Network devices
181  */
182 
183 struct ic_device {
184 	struct ic_device *next;
185 	struct net_device *dev;
186 	unsigned short flags;
187 	short able;
188 	__be32 xid;
189 };
190 
191 static struct ic_device *ic_first_dev __initdata;	/* List of open device */
192 static struct ic_device *ic_dev __initdata;		/* Selected device */
193 
194 static bool __init ic_is_init_dev(struct net_device *dev)
195 {
196 	if (dev->flags & IFF_LOOPBACK)
197 		return false;
198 	return user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
199 	    (!(dev->flags & IFF_LOOPBACK) &&
200 	     (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
201 	     strncmp(dev->name, "dummy", 5));
202 }
203 
204 static int __init ic_open_devs(void)
205 {
206 	struct ic_device *d, **last;
207 	struct net_device *dev;
208 	unsigned short oflags;
209 	unsigned long start, next_msg;
210 
211 	last = &ic_first_dev;
212 	rtnl_lock();
213 
214 	/* bring loopback and DSA master network devices up first */
215 	for_each_netdev(&init_net, dev) {
216 		if (!(dev->flags & IFF_LOOPBACK) && !netdev_uses_dsa(dev))
217 			continue;
218 		if (dev_change_flags(dev, dev->flags | IFF_UP) < 0)
219 			pr_err("IP-Config: Failed to open %s\n", dev->name);
220 	}
221 
222 	for_each_netdev(&init_net, dev) {
223 		if (ic_is_init_dev(dev)) {
224 			int able = 0;
225 			if (dev->mtu >= 364)
226 				able |= IC_BOOTP;
227 			else
228 				pr_warn("DHCP/BOOTP: Ignoring device %s, MTU %d too small\n",
229 					dev->name, dev->mtu);
230 			if (!(dev->flags & IFF_NOARP))
231 				able |= IC_RARP;
232 			able &= ic_proto_enabled;
233 			if (ic_proto_enabled && !able)
234 				continue;
235 			oflags = dev->flags;
236 			if (dev_change_flags(dev, oflags | IFF_UP) < 0) {
237 				pr_err("IP-Config: Failed to open %s\n",
238 				       dev->name);
239 				continue;
240 			}
241 			if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
242 				rtnl_unlock();
243 				return -ENOMEM;
244 			}
245 			d->dev = dev;
246 			*last = d;
247 			last = &d->next;
248 			d->flags = oflags;
249 			d->able = able;
250 			if (able & IC_BOOTP)
251 				get_random_bytes(&d->xid, sizeof(__be32));
252 			else
253 				d->xid = 0;
254 			ic_proto_have_if |= able;
255 			pr_debug("IP-Config: %s UP (able=%d, xid=%08x)\n",
256 				 dev->name, able, d->xid);
257 		}
258 	}
259 
260 	/* no point in waiting if we could not bring up at least one device */
261 	if (!ic_first_dev)
262 		goto have_carrier;
263 
264 	/* wait for a carrier on at least one device */
265 	start = jiffies;
266 	next_msg = start + msecs_to_jiffies(CONF_CARRIER_TIMEOUT/12);
267 	while (time_before(jiffies, start +
268 			   msecs_to_jiffies(CONF_CARRIER_TIMEOUT))) {
269 		int wait, elapsed;
270 
271 		for_each_netdev(&init_net, dev)
272 			if (ic_is_init_dev(dev) && netif_carrier_ok(dev))
273 				goto have_carrier;
274 
275 		msleep(1);
276 
277 		if (time_before(jiffies, next_msg))
278 			continue;
279 
280 		elapsed = jiffies_to_msecs(jiffies - start);
281 		wait = (CONF_CARRIER_TIMEOUT - elapsed + 500)/1000;
282 		pr_info("Waiting up to %d more seconds for network.\n", wait);
283 		next_msg = jiffies + msecs_to_jiffies(CONF_CARRIER_TIMEOUT/12);
284 	}
285 have_carrier:
286 	rtnl_unlock();
287 
288 	*last = NULL;
289 
290 	if (!ic_first_dev) {
291 		if (user_dev_name[0])
292 			pr_err("IP-Config: Device `%s' not found\n",
293 			       user_dev_name);
294 		else
295 			pr_err("IP-Config: No network devices available\n");
296 		return -ENODEV;
297 	}
298 	return 0;
299 }
300 
301 static void __init ic_close_devs(void)
302 {
303 	struct ic_device *d, *next;
304 	struct net_device *dev;
305 
306 	rtnl_lock();
307 	next = ic_first_dev;
308 	while ((d = next)) {
309 		next = d->next;
310 		dev = d->dev;
311 		if (d != ic_dev && !netdev_uses_dsa(dev)) {
312 			pr_debug("IP-Config: Downing %s\n", dev->name);
313 			dev_change_flags(dev, d->flags);
314 		}
315 		kfree(d);
316 	}
317 	rtnl_unlock();
318 }
319 
320 /*
321  *	Interface to various network functions.
322  */
323 
324 static inline void
325 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
326 {
327 	sin->sin_family = AF_INET;
328 	sin->sin_addr.s_addr = addr;
329 	sin->sin_port = port;
330 }
331 
332 static int __init ic_devinet_ioctl(unsigned int cmd, struct ifreq *arg)
333 {
334 	int res;
335 
336 	mm_segment_t oldfs = get_fs();
337 	set_fs(get_ds());
338 	res = devinet_ioctl(&init_net, cmd, (struct ifreq __user *) arg);
339 	set_fs(oldfs);
340 	return res;
341 }
342 
343 static int __init ic_dev_ioctl(unsigned int cmd, struct ifreq *arg)
344 {
345 	int res;
346 
347 	mm_segment_t oldfs = get_fs();
348 	set_fs(get_ds());
349 	res = dev_ioctl(&init_net, cmd, (struct ifreq __user *) arg);
350 	set_fs(oldfs);
351 	return res;
352 }
353 
354 static int __init ic_route_ioctl(unsigned int cmd, struct rtentry *arg)
355 {
356 	int res;
357 
358 	mm_segment_t oldfs = get_fs();
359 	set_fs(get_ds());
360 	res = ip_rt_ioctl(&init_net, cmd, (void __user *) arg);
361 	set_fs(oldfs);
362 	return res;
363 }
364 
365 /*
366  *	Set up interface addresses and routes.
367  */
368 
369 static int __init ic_setup_if(void)
370 {
371 	struct ifreq ir;
372 	struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
373 	int err;
374 
375 	memset(&ir, 0, sizeof(ir));
376 	strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->dev->name);
377 	set_sockaddr(sin, ic_myaddr, 0);
378 	if ((err = ic_devinet_ioctl(SIOCSIFADDR, &ir)) < 0) {
379 		pr_err("IP-Config: Unable to set interface address (%d)\n",
380 		       err);
381 		return -1;
382 	}
383 	set_sockaddr(sin, ic_netmask, 0);
384 	if ((err = ic_devinet_ioctl(SIOCSIFNETMASK, &ir)) < 0) {
385 		pr_err("IP-Config: Unable to set interface netmask (%d)\n",
386 		       err);
387 		return -1;
388 	}
389 	set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
390 	if ((err = ic_devinet_ioctl(SIOCSIFBRDADDR, &ir)) < 0) {
391 		pr_err("IP-Config: Unable to set interface broadcast address (%d)\n",
392 		       err);
393 		return -1;
394 	}
395 	/* Handle the case where we need non-standard MTU on the boot link (a network
396 	 * using jumbo frames, for instance).  If we can't set the mtu, don't error
397 	 * out, we'll try to muddle along.
398 	 */
399 	if (ic_dev_mtu != 0) {
400 		strcpy(ir.ifr_name, ic_dev->dev->name);
401 		ir.ifr_mtu = ic_dev_mtu;
402 		if ((err = ic_dev_ioctl(SIOCSIFMTU, &ir)) < 0)
403 			pr_err("IP-Config: Unable to set interface mtu to %d (%d)\n",
404 			       ic_dev_mtu, err);
405 	}
406 	return 0;
407 }
408 
409 static int __init ic_setup_routes(void)
410 {
411 	/* No need to setup device routes, only the default route... */
412 
413 	if (ic_gateway != NONE) {
414 		struct rtentry rm;
415 		int err;
416 
417 		memset(&rm, 0, sizeof(rm));
418 		if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
419 			pr_err("IP-Config: Gateway not on directly connected network\n");
420 			return -1;
421 		}
422 		set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
423 		set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
424 		set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
425 		rm.rt_flags = RTF_UP | RTF_GATEWAY;
426 		if ((err = ic_route_ioctl(SIOCADDRT, &rm)) < 0) {
427 			pr_err("IP-Config: Cannot add default route (%d)\n",
428 			       err);
429 			return -1;
430 		}
431 	}
432 
433 	return 0;
434 }
435 
436 /*
437  *	Fill in default values for all missing parameters.
438  */
439 
440 static int __init ic_defaults(void)
441 {
442 	/*
443 	 *	At this point we have no userspace running so need not
444 	 *	claim locks on system_utsname
445 	 */
446 
447 	if (!ic_host_name_set)
448 		sprintf(init_utsname()->nodename, "%pI4", &ic_myaddr);
449 
450 	if (root_server_addr == NONE)
451 		root_server_addr = ic_servaddr;
452 
453 	if (ic_netmask == NONE) {
454 		if (IN_CLASSA(ntohl(ic_myaddr)))
455 			ic_netmask = htonl(IN_CLASSA_NET);
456 		else if (IN_CLASSB(ntohl(ic_myaddr)))
457 			ic_netmask = htonl(IN_CLASSB_NET);
458 		else if (IN_CLASSC(ntohl(ic_myaddr)))
459 			ic_netmask = htonl(IN_CLASSC_NET);
460 		else {
461 			pr_err("IP-Config: Unable to guess netmask for address %pI4\n",
462 			       &ic_myaddr);
463 			return -1;
464 		}
465 		pr_notice("IP-Config: Guessing netmask %pI4\n",
466 			  &ic_netmask);
467 	}
468 
469 	return 0;
470 }
471 
472 /*
473  *	RARP support.
474  */
475 
476 #ifdef IPCONFIG_RARP
477 
478 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
479 
480 static struct packet_type rarp_packet_type __initdata = {
481 	.type =	cpu_to_be16(ETH_P_RARP),
482 	.func =	ic_rarp_recv,
483 };
484 
485 static inline void __init ic_rarp_init(void)
486 {
487 	dev_add_pack(&rarp_packet_type);
488 }
489 
490 static inline void __init ic_rarp_cleanup(void)
491 {
492 	dev_remove_pack(&rarp_packet_type);
493 }
494 
495 /*
496  *  Process received RARP packet.
497  */
498 static int __init
499 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
500 {
501 	struct arphdr *rarp;
502 	unsigned char *rarp_ptr;
503 	__be32 sip, tip;
504 	unsigned char *tha;		/* t for "target" */
505 	struct ic_device *d;
506 
507 	if (!net_eq(dev_net(dev), &init_net))
508 		goto drop;
509 
510 	skb = skb_share_check(skb, GFP_ATOMIC);
511 	if (!skb)
512 		return NET_RX_DROP;
513 
514 	if (!pskb_may_pull(skb, sizeof(struct arphdr)))
515 		goto drop;
516 
517 	/* Basic sanity checks can be done without the lock.  */
518 	rarp = (struct arphdr *)skb_transport_header(skb);
519 
520 	/* If this test doesn't pass, it's not IP, or we should
521 	 * ignore it anyway.
522 	 */
523 	if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
524 		goto drop;
525 
526 	/* If it's not a RARP reply, delete it. */
527 	if (rarp->ar_op != htons(ARPOP_RREPLY))
528 		goto drop;
529 
530 	/* If it's not Ethernet, delete it. */
531 	if (rarp->ar_pro != htons(ETH_P_IP))
532 		goto drop;
533 
534 	if (!pskb_may_pull(skb, arp_hdr_len(dev)))
535 		goto drop;
536 
537 	/* OK, it is all there and looks valid, process... */
538 	rarp = (struct arphdr *)skb_transport_header(skb);
539 	rarp_ptr = (unsigned char *) (rarp + 1);
540 
541 	/* One reply at a time, please. */
542 	spin_lock(&ic_recv_lock);
543 
544 	/* If we already have a reply, just drop the packet */
545 	if (ic_got_reply)
546 		goto drop_unlock;
547 
548 	/* Find the ic_device that the packet arrived on */
549 	d = ic_first_dev;
550 	while (d && d->dev != dev)
551 		d = d->next;
552 	if (!d)
553 		goto drop_unlock;	/* should never happen */
554 
555 	/* Extract variable-width fields */
556 	rarp_ptr += dev->addr_len;
557 	memcpy(&sip, rarp_ptr, 4);
558 	rarp_ptr += 4;
559 	tha = rarp_ptr;
560 	rarp_ptr += dev->addr_len;
561 	memcpy(&tip, rarp_ptr, 4);
562 
563 	/* Discard packets which are not meant for us. */
564 	if (memcmp(tha, dev->dev_addr, dev->addr_len))
565 		goto drop_unlock;
566 
567 	/* Discard packets which are not from specified server. */
568 	if (ic_servaddr != NONE && ic_servaddr != sip)
569 		goto drop_unlock;
570 
571 	/* We have a winner! */
572 	ic_dev = d;
573 	if (ic_myaddr == NONE)
574 		ic_myaddr = tip;
575 	ic_servaddr = sip;
576 	ic_addrservaddr = sip;
577 	ic_got_reply = IC_RARP;
578 
579 drop_unlock:
580 	/* Show's over.  Nothing to see here.  */
581 	spin_unlock(&ic_recv_lock);
582 
583 drop:
584 	/* Throw the packet out. */
585 	kfree_skb(skb);
586 	return 0;
587 }
588 
589 
590 /*
591  *  Send RARP request packet over a single interface.
592  */
593 static void __init ic_rarp_send_if(struct ic_device *d)
594 {
595 	struct net_device *dev = d->dev;
596 	arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
597 		 dev->dev_addr, dev->dev_addr);
598 }
599 #endif
600 
601 /*
602  *  Predefine Nameservers
603  */
604 static inline void __init ic_nameservers_predef(void)
605 {
606 	int i;
607 
608 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
609 		ic_nameservers[i] = NONE;
610 }
611 
612 /*
613  *	DHCP/BOOTP support.
614  */
615 
616 #ifdef IPCONFIG_BOOTP
617 
618 struct bootp_pkt {		/* BOOTP packet format */
619 	struct iphdr iph;	/* IP header */
620 	struct udphdr udph;	/* UDP header */
621 	u8 op;			/* 1=request, 2=reply */
622 	u8 htype;		/* HW address type */
623 	u8 hlen;		/* HW address length */
624 	u8 hops;		/* Used only by gateways */
625 	__be32 xid;		/* Transaction ID */
626 	__be16 secs;		/* Seconds since we started */
627 	__be16 flags;		/* Just what it says */
628 	__be32 client_ip;		/* Client's IP address if known */
629 	__be32 your_ip;		/* Assigned IP address */
630 	__be32 server_ip;		/* (Next, e.g. NFS) Server's IP address */
631 	__be32 relay_ip;		/* IP address of BOOTP relay */
632 	u8 hw_addr[16];		/* Client's HW address */
633 	u8 serv_name[64];	/* Server host name */
634 	u8 boot_file[128];	/* Name of boot file */
635 	u8 exten[312];		/* DHCP options / BOOTP vendor extensions */
636 };
637 
638 /* packet ops */
639 #define BOOTP_REQUEST	1
640 #define BOOTP_REPLY	2
641 
642 /* DHCP message types */
643 #define DHCPDISCOVER	1
644 #define DHCPOFFER	2
645 #define DHCPREQUEST	3
646 #define DHCPDECLINE	4
647 #define DHCPACK		5
648 #define DHCPNAK		6
649 #define DHCPRELEASE	7
650 #define DHCPINFORM	8
651 
652 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
653 
654 static struct packet_type bootp_packet_type __initdata = {
655 	.type =	cpu_to_be16(ETH_P_IP),
656 	.func =	ic_bootp_recv,
657 };
658 
659 /*
660  *  Initialize DHCP/BOOTP extension fields in the request.
661  */
662 
663 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
664 
665 #ifdef IPCONFIG_DHCP
666 
667 static void __init
668 ic_dhcp_init_options(u8 *options, struct ic_device *d)
669 {
670 	u8 mt = ((ic_servaddr == NONE)
671 		 ? DHCPDISCOVER : DHCPREQUEST);
672 	u8 *e = options;
673 	int len;
674 
675 	pr_debug("DHCP: Sending message type %d (%s)\n", mt, d->dev->name);
676 
677 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
678 	e += 4;
679 
680 	*e++ = 53;		/* DHCP message type */
681 	*e++ = 1;
682 	*e++ = mt;
683 
684 	if (mt == DHCPREQUEST) {
685 		*e++ = 54;	/* Server ID (IP address) */
686 		*e++ = 4;
687 		memcpy(e, &ic_servaddr, 4);
688 		e += 4;
689 
690 		*e++ = 50;	/* Requested IP address */
691 		*e++ = 4;
692 		memcpy(e, &ic_myaddr, 4);
693 		e += 4;
694 	}
695 
696 	/* always? */
697 	{
698 		static const u8 ic_req_params[] = {
699 			1,	/* Subnet mask */
700 			3,	/* Default gateway */
701 			6,	/* DNS server */
702 			12,	/* Host name */
703 			15,	/* Domain name */
704 			17,	/* Boot path */
705 			26,	/* MTU */
706 			40,	/* NIS domain name */
707 		};
708 
709 		*e++ = 55;	/* Parameter request list */
710 		*e++ = sizeof(ic_req_params);
711 		memcpy(e, ic_req_params, sizeof(ic_req_params));
712 		e += sizeof(ic_req_params);
713 
714 		if (ic_host_name_set) {
715 			*e++ = 12;	/* host-name */
716 			len = strlen(utsname()->nodename);
717 			*e++ = len;
718 			memcpy(e, utsname()->nodename, len);
719 			e += len;
720 		}
721 		if (*vendor_class_identifier) {
722 			pr_info("DHCP: sending class identifier \"%s\"\n",
723 				vendor_class_identifier);
724 			*e++ = 60;	/* Class-identifier */
725 			len = strlen(vendor_class_identifier);
726 			*e++ = len;
727 			memcpy(e, vendor_class_identifier, len);
728 			e += len;
729 		}
730 		len = strlen(dhcp_client_identifier + 1);
731 		/* the minimum length of identifier is 2, include 1 byte type,
732 		 * and can not be larger than the length of options
733 		 */
734 		if (len >= 1 && len < 312 - (e - options) - 1) {
735 			*e++ = 61;
736 			*e++ = len + 1;
737 			memcpy(e, dhcp_client_identifier, len + 1);
738 			e += len + 1;
739 		}
740 	}
741 
742 	*e++ = 255;	/* End of the list */
743 }
744 
745 #endif /* IPCONFIG_DHCP */
746 
747 static void __init ic_bootp_init_ext(u8 *e)
748 {
749 	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
750 	e += 4;
751 	*e++ = 1;		/* Subnet mask request */
752 	*e++ = 4;
753 	e += 4;
754 	*e++ = 3;		/* Default gateway request */
755 	*e++ = 4;
756 	e += 4;
757 	*e++ = 5;		/* Name server request */
758 	*e++ = 8;
759 	e += 8;
760 	*e++ = 12;		/* Host name request */
761 	*e++ = 32;
762 	e += 32;
763 	*e++ = 40;		/* NIS Domain name request */
764 	*e++ = 32;
765 	e += 32;
766 	*e++ = 17;		/* Boot path */
767 	*e++ = 40;
768 	e += 40;
769 
770 	*e++ = 57;		/* set extension buffer size for reply */
771 	*e++ = 2;
772 	*e++ = 1;		/* 128+236+8+20+14, see dhcpd sources */
773 	*e++ = 150;
774 
775 	*e++ = 255;		/* End of the list */
776 }
777 
778 
779 /*
780  *  Initialize the DHCP/BOOTP mechanism.
781  */
782 static inline void __init ic_bootp_init(void)
783 {
784 	ic_nameservers_predef();
785 
786 	dev_add_pack(&bootp_packet_type);
787 }
788 
789 
790 /*
791  *  DHCP/BOOTP cleanup.
792  */
793 static inline void __init ic_bootp_cleanup(void)
794 {
795 	dev_remove_pack(&bootp_packet_type);
796 }
797 
798 
799 /*
800  *  Send DHCP/BOOTP request to single interface.
801  */
802 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
803 {
804 	struct net_device *dev = d->dev;
805 	struct sk_buff *skb;
806 	struct bootp_pkt *b;
807 	struct iphdr *h;
808 	int hlen = LL_RESERVED_SPACE(dev);
809 	int tlen = dev->needed_tailroom;
810 
811 	/* Allocate packet */
812 	skb = alloc_skb(sizeof(struct bootp_pkt) + hlen + tlen + 15,
813 			GFP_KERNEL);
814 	if (!skb)
815 		return;
816 	skb_reserve(skb, hlen);
817 	b = skb_put_zero(skb, sizeof(struct bootp_pkt));
818 
819 	/* Construct IP header */
820 	skb_reset_network_header(skb);
821 	h = ip_hdr(skb);
822 	h->version = 4;
823 	h->ihl = 5;
824 	h->tot_len = htons(sizeof(struct bootp_pkt));
825 	h->frag_off = htons(IP_DF);
826 	h->ttl = 64;
827 	h->protocol = IPPROTO_UDP;
828 	h->daddr = htonl(INADDR_BROADCAST);
829 	h->check = ip_fast_csum((unsigned char *) h, h->ihl);
830 
831 	/* Construct UDP header */
832 	b->udph.source = htons(68);
833 	b->udph.dest = htons(67);
834 	b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
835 	/* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
836 
837 	/* Construct DHCP/BOOTP header */
838 	b->op = BOOTP_REQUEST;
839 	if (dev->type < 256) /* check for false types */
840 		b->htype = dev->type;
841 	else if (dev->type == ARPHRD_FDDI)
842 		b->htype = ARPHRD_ETHER;
843 	else {
844 		pr_warn("Unknown ARP type 0x%04x for device %s\n", dev->type,
845 			dev->name);
846 		b->htype = dev->type; /* can cause undefined behavior */
847 	}
848 
849 	/* server_ip and your_ip address are both already zero per RFC2131 */
850 	b->hlen = dev->addr_len;
851 	memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
852 	b->secs = htons(jiffies_diff / HZ);
853 	b->xid = d->xid;
854 
855 	/* add DHCP options or BOOTP extensions */
856 #ifdef IPCONFIG_DHCP
857 	if (ic_proto_enabled & IC_USE_DHCP)
858 		ic_dhcp_init_options(b->exten, d);
859 	else
860 #endif
861 		ic_bootp_init_ext(b->exten);
862 
863 	/* Chain packet down the line... */
864 	skb->dev = dev;
865 	skb->protocol = htons(ETH_P_IP);
866 	if (dev_hard_header(skb, dev, ntohs(skb->protocol),
867 			    dev->broadcast, dev->dev_addr, skb->len) < 0) {
868 		kfree_skb(skb);
869 		printk("E");
870 		return;
871 	}
872 
873 	if (dev_queue_xmit(skb) < 0)
874 		printk("E");
875 }
876 
877 
878 /*
879  *  Copy BOOTP-supplied string if not already set.
880  */
881 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
882 {
883 	if (!len)
884 		return 0;
885 	if (len > max-1)
886 		len = max-1;
887 	memcpy(dest, src, len);
888 	dest[len] = '\0';
889 	return 1;
890 }
891 
892 
893 /*
894  *  Process BOOTP extensions.
895  */
896 static void __init ic_do_bootp_ext(u8 *ext)
897 {
898 	u8 servers;
899 	int i;
900 	__be16 mtu;
901 
902 	u8 *c;
903 
904 	pr_debug("DHCP/BOOTP: Got extension %d:", *ext);
905 	for (c=ext+2; c<ext+2+ext[1]; c++)
906 		pr_debug(" %02x", *c);
907 	pr_debug("\n");
908 
909 	switch (*ext++) {
910 	case 1:		/* Subnet mask */
911 		if (ic_netmask == NONE)
912 			memcpy(&ic_netmask, ext+1, 4);
913 		break;
914 	case 3:		/* Default gateway */
915 		if (ic_gateway == NONE)
916 			memcpy(&ic_gateway, ext+1, 4);
917 		break;
918 	case 6:		/* DNS server */
919 		servers= *ext/4;
920 		if (servers > CONF_NAMESERVERS_MAX)
921 			servers = CONF_NAMESERVERS_MAX;
922 		for (i = 0; i < servers; i++) {
923 			if (ic_nameservers[i] == NONE)
924 				memcpy(&ic_nameservers[i], ext+1+4*i, 4);
925 		}
926 		break;
927 	case 12:	/* Host name */
928 		ic_bootp_string(utsname()->nodename, ext+1, *ext,
929 				__NEW_UTS_LEN);
930 		ic_host_name_set = 1;
931 		break;
932 	case 15:	/* Domain name (DNS) */
933 		ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
934 		break;
935 	case 17:	/* Root path */
936 		if (!root_server_path[0])
937 			ic_bootp_string(root_server_path, ext+1, *ext,
938 					sizeof(root_server_path));
939 		break;
940 	case 26:	/* Interface MTU */
941 		memcpy(&mtu, ext+1, sizeof(mtu));
942 		ic_dev_mtu = ntohs(mtu);
943 		break;
944 	case 40:	/* NIS Domain name (_not_ DNS) */
945 		ic_bootp_string(utsname()->domainname, ext+1, *ext,
946 				__NEW_UTS_LEN);
947 		break;
948 	}
949 }
950 
951 
952 /*
953  *  Receive BOOTP reply.
954  */
955 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
956 {
957 	struct bootp_pkt *b;
958 	struct iphdr *h;
959 	struct ic_device *d;
960 	int len, ext_len;
961 
962 	if (!net_eq(dev_net(dev), &init_net))
963 		goto drop;
964 
965 	/* Perform verifications before taking the lock.  */
966 	if (skb->pkt_type == PACKET_OTHERHOST)
967 		goto drop;
968 
969 	skb = skb_share_check(skb, GFP_ATOMIC);
970 	if (!skb)
971 		return NET_RX_DROP;
972 
973 	if (!pskb_may_pull(skb,
974 			   sizeof(struct iphdr) +
975 			   sizeof(struct udphdr)))
976 		goto drop;
977 
978 	b = (struct bootp_pkt *)skb_network_header(skb);
979 	h = &b->iph;
980 
981 	if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
982 		goto drop;
983 
984 	/* Fragments are not supported */
985 	if (ip_is_fragment(h)) {
986 		net_err_ratelimited("DHCP/BOOTP: Ignoring fragmented reply\n");
987 		goto drop;
988 	}
989 
990 	if (skb->len < ntohs(h->tot_len))
991 		goto drop;
992 
993 	if (ip_fast_csum((char *) h, h->ihl))
994 		goto drop;
995 
996 	if (b->udph.source != htons(67) || b->udph.dest != htons(68))
997 		goto drop;
998 
999 	if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
1000 		goto drop;
1001 
1002 	len = ntohs(b->udph.len) - sizeof(struct udphdr);
1003 	ext_len = len - (sizeof(*b) -
1004 			 sizeof(struct iphdr) -
1005 			 sizeof(struct udphdr) -
1006 			 sizeof(b->exten));
1007 	if (ext_len < 0)
1008 		goto drop;
1009 
1010 	/* Ok the front looks good, make sure we can get at the rest.  */
1011 	if (!pskb_may_pull(skb, skb->len))
1012 		goto drop;
1013 
1014 	b = (struct bootp_pkt *)skb_network_header(skb);
1015 	h = &b->iph;
1016 
1017 	/* One reply at a time, please. */
1018 	spin_lock(&ic_recv_lock);
1019 
1020 	/* If we already have a reply, just drop the packet */
1021 	if (ic_got_reply)
1022 		goto drop_unlock;
1023 
1024 	/* Find the ic_device that the packet arrived on */
1025 	d = ic_first_dev;
1026 	while (d && d->dev != dev)
1027 		d = d->next;
1028 	if (!d)
1029 		goto drop_unlock;  /* should never happen */
1030 
1031 	/* Is it a reply to our BOOTP request? */
1032 	if (b->op != BOOTP_REPLY ||
1033 	    b->xid != d->xid) {
1034 		net_err_ratelimited("DHCP/BOOTP: Reply not for us on %s, op[%x] xid[%x]\n",
1035 				    d->dev->name, b->op, b->xid);
1036 		goto drop_unlock;
1037 	}
1038 
1039 	/* Parse extensions */
1040 	if (ext_len >= 4 &&
1041 	    !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
1042 		u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
1043 		u8 *ext;
1044 
1045 #ifdef IPCONFIG_DHCP
1046 		if (ic_proto_enabled & IC_USE_DHCP) {
1047 			__be32 server_id = NONE;
1048 			int mt = 0;
1049 
1050 			ext = &b->exten[4];
1051 			while (ext < end && *ext != 0xff) {
1052 				u8 *opt = ext++;
1053 				if (*opt == 0)	/* Padding */
1054 					continue;
1055 				ext += *ext + 1;
1056 				if (ext >= end)
1057 					break;
1058 				switch (*opt) {
1059 				case 53:	/* Message type */
1060 					if (opt[1])
1061 						mt = opt[2];
1062 					break;
1063 				case 54:	/* Server ID (IP address) */
1064 					if (opt[1] >= 4)
1065 						memcpy(&server_id, opt + 2, 4);
1066 					break;
1067 				}
1068 			}
1069 
1070 			pr_debug("DHCP: Got message type %d (%s)\n", mt, d->dev->name);
1071 
1072 			switch (mt) {
1073 			case DHCPOFFER:
1074 				/* While in the process of accepting one offer,
1075 				 * ignore all others.
1076 				 */
1077 				if (ic_myaddr != NONE)
1078 					goto drop_unlock;
1079 
1080 				/* Let's accept that offer. */
1081 				ic_myaddr = b->your_ip;
1082 				ic_servaddr = server_id;
1083 				pr_debug("DHCP: Offered address %pI4 by server %pI4\n",
1084 					 &ic_myaddr, &b->iph.saddr);
1085 				/* The DHCP indicated server address takes
1086 				 * precedence over the bootp header one if
1087 				 * they are different.
1088 				 */
1089 				if ((server_id != NONE) &&
1090 				    (b->server_ip != server_id))
1091 					b->server_ip = ic_servaddr;
1092 				break;
1093 
1094 			case DHCPACK:
1095 				if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1096 					goto drop_unlock;
1097 
1098 				/* Yeah! */
1099 				break;
1100 
1101 			default:
1102 				/* Urque.  Forget it*/
1103 				ic_myaddr = NONE;
1104 				ic_servaddr = NONE;
1105 				goto drop_unlock;
1106 			}
1107 
1108 			ic_dhcp_msgtype = mt;
1109 
1110 		}
1111 #endif /* IPCONFIG_DHCP */
1112 
1113 		ext = &b->exten[4];
1114 		while (ext < end && *ext != 0xff) {
1115 			u8 *opt = ext++;
1116 			if (*opt == 0)	/* Padding */
1117 				continue;
1118 			ext += *ext + 1;
1119 			if (ext < end)
1120 				ic_do_bootp_ext(opt);
1121 		}
1122 	}
1123 
1124 	/* We have a winner! */
1125 	ic_dev = d;
1126 	ic_myaddr = b->your_ip;
1127 	ic_servaddr = b->server_ip;
1128 	ic_addrservaddr = b->iph.saddr;
1129 	if (ic_gateway == NONE && b->relay_ip)
1130 		ic_gateway = b->relay_ip;
1131 	if (ic_nameservers[0] == NONE)
1132 		ic_nameservers[0] = ic_servaddr;
1133 	ic_got_reply = IC_BOOTP;
1134 
1135 drop_unlock:
1136 	/* Show's over.  Nothing to see here.  */
1137 	spin_unlock(&ic_recv_lock);
1138 
1139 drop:
1140 	/* Throw the packet out. */
1141 	kfree_skb(skb);
1142 
1143 	return 0;
1144 }
1145 
1146 
1147 #endif
1148 
1149 
1150 /*
1151  *	Dynamic IP configuration -- DHCP, BOOTP, RARP.
1152  */
1153 
1154 #ifdef IPCONFIG_DYNAMIC
1155 
1156 static int __init ic_dynamic(void)
1157 {
1158 	int retries;
1159 	struct ic_device *d;
1160 	unsigned long start_jiffies, timeout, jiff;
1161 	int do_bootp = ic_proto_have_if & IC_BOOTP;
1162 	int do_rarp = ic_proto_have_if & IC_RARP;
1163 
1164 	/*
1165 	 * If none of DHCP/BOOTP/RARP was selected, return with an error.
1166 	 * This routine gets only called when some pieces of information
1167 	 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1168 	 */
1169 	if (!ic_proto_enabled) {
1170 		pr_err("IP-Config: Incomplete network configuration information\n");
1171 		return -1;
1172 	}
1173 
1174 #ifdef IPCONFIG_BOOTP
1175 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1176 		pr_err("DHCP/BOOTP: No suitable device found\n");
1177 #endif
1178 #ifdef IPCONFIG_RARP
1179 	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1180 		pr_err("RARP: No suitable device found\n");
1181 #endif
1182 
1183 	if (!ic_proto_have_if)
1184 		/* Error message already printed */
1185 		return -1;
1186 
1187 	/*
1188 	 * Setup protocols
1189 	 */
1190 #ifdef IPCONFIG_BOOTP
1191 	if (do_bootp)
1192 		ic_bootp_init();
1193 #endif
1194 #ifdef IPCONFIG_RARP
1195 	if (do_rarp)
1196 		ic_rarp_init();
1197 #endif
1198 
1199 	/*
1200 	 * Send requests and wait, until we get an answer. This loop
1201 	 * seems to be a terrible waste of CPU time, but actually there is
1202 	 * only one process running at all, so we don't need to use any
1203 	 * scheduler functions.
1204 	 * [Actually we could now, but the nothing else running note still
1205 	 *  applies.. - AC]
1206 	 */
1207 	pr_notice("Sending %s%s%s requests .",
1208 		  do_bootp
1209 		  ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1210 		  (do_bootp && do_rarp) ? " and " : "",
1211 		  do_rarp ? "RARP" : "");
1212 
1213 	start_jiffies = jiffies;
1214 	d = ic_first_dev;
1215 	retries = CONF_SEND_RETRIES;
1216 	get_random_bytes(&timeout, sizeof(timeout));
1217 	timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned int) CONF_TIMEOUT_RANDOM);
1218 	for (;;) {
1219 #ifdef IPCONFIG_BOOTP
1220 		if (do_bootp && (d->able & IC_BOOTP))
1221 			ic_bootp_send_if(d, jiffies - start_jiffies);
1222 #endif
1223 #ifdef IPCONFIG_RARP
1224 		if (do_rarp && (d->able & IC_RARP))
1225 			ic_rarp_send_if(d);
1226 #endif
1227 
1228 		if (!d->next) {
1229 			jiff = jiffies + timeout;
1230 			while (time_before(jiffies, jiff) && !ic_got_reply)
1231 				schedule_timeout_uninterruptible(1);
1232 		}
1233 #ifdef IPCONFIG_DHCP
1234 		/* DHCP isn't done until we get a DHCPACK. */
1235 		if ((ic_got_reply & IC_BOOTP) &&
1236 		    (ic_proto_enabled & IC_USE_DHCP) &&
1237 		    ic_dhcp_msgtype != DHCPACK) {
1238 			ic_got_reply = 0;
1239 			/* continue on device that got the reply */
1240 			d = ic_dev;
1241 			pr_cont(",");
1242 			continue;
1243 		}
1244 #endif /* IPCONFIG_DHCP */
1245 
1246 		if (ic_got_reply) {
1247 			pr_cont(" OK\n");
1248 			break;
1249 		}
1250 
1251 		if ((d = d->next))
1252 			continue;
1253 
1254 		if (! --retries) {
1255 			pr_cont(" timed out!\n");
1256 			break;
1257 		}
1258 
1259 		d = ic_first_dev;
1260 
1261 		timeout = timeout CONF_TIMEOUT_MULT;
1262 		if (timeout > CONF_TIMEOUT_MAX)
1263 			timeout = CONF_TIMEOUT_MAX;
1264 
1265 		pr_cont(".");
1266 	}
1267 
1268 #ifdef IPCONFIG_BOOTP
1269 	if (do_bootp)
1270 		ic_bootp_cleanup();
1271 #endif
1272 #ifdef IPCONFIG_RARP
1273 	if (do_rarp)
1274 		ic_rarp_cleanup();
1275 #endif
1276 
1277 	if (!ic_got_reply) {
1278 		ic_myaddr = NONE;
1279 		return -1;
1280 	}
1281 
1282 	pr_info("IP-Config: Got %s answer from %pI4, my address is %pI4\n",
1283 		((ic_got_reply & IC_RARP) ? "RARP"
1284 		: (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1285 		&ic_addrservaddr, &ic_myaddr);
1286 
1287 	return 0;
1288 }
1289 
1290 #endif /* IPCONFIG_DYNAMIC */
1291 
1292 #ifdef CONFIG_PROC_FS
1293 
1294 static int pnp_seq_show(struct seq_file *seq, void *v)
1295 {
1296 	int i;
1297 
1298 	if (ic_proto_used & IC_PROTO)
1299 		seq_printf(seq, "#PROTO: %s\n",
1300 			   (ic_proto_used & IC_RARP) ? "RARP"
1301 			   : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1302 	else
1303 		seq_puts(seq, "#MANUAL\n");
1304 
1305 	if (ic_domain[0])
1306 		seq_printf(seq,
1307 			   "domain %s\n", ic_domain);
1308 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1309 		if (ic_nameservers[i] != NONE)
1310 			seq_printf(seq, "nameserver %pI4\n",
1311 				   &ic_nameservers[i]);
1312 	}
1313 	if (ic_servaddr != NONE)
1314 		seq_printf(seq, "bootserver %pI4\n",
1315 			   &ic_servaddr);
1316 	return 0;
1317 }
1318 
1319 static int pnp_seq_open(struct inode *indoe, struct file *file)
1320 {
1321 	return single_open(file, pnp_seq_show, NULL);
1322 }
1323 
1324 static const struct file_operations pnp_seq_fops = {
1325 	.owner		= THIS_MODULE,
1326 	.open		= pnp_seq_open,
1327 	.read		= seq_read,
1328 	.llseek		= seq_lseek,
1329 	.release	= single_release,
1330 };
1331 #endif /* CONFIG_PROC_FS */
1332 
1333 /*
1334  *  Extract IP address from the parameter string if needed. Note that we
1335  *  need to have root_server_addr set _before_ IPConfig gets called as it
1336  *  can override it.
1337  */
1338 __be32 __init root_nfs_parse_addr(char *name)
1339 {
1340 	__be32 addr;
1341 	int octets = 0;
1342 	char *cp, *cq;
1343 
1344 	cp = cq = name;
1345 	while (octets < 4) {
1346 		while (*cp >= '0' && *cp <= '9')
1347 			cp++;
1348 		if (cp == cq || cp - cq > 3)
1349 			break;
1350 		if (*cp == '.' || octets == 3)
1351 			octets++;
1352 		if (octets < 4)
1353 			cp++;
1354 		cq = cp;
1355 	}
1356 	if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1357 		if (*cp == ':')
1358 			*cp++ = '\0';
1359 		addr = in_aton(name);
1360 		memmove(name, cp, strlen(cp) + 1);
1361 	} else
1362 		addr = NONE;
1363 
1364 	return addr;
1365 }
1366 
1367 #define DEVICE_WAIT_MAX		12 /* 12 seconds */
1368 
1369 static int __init wait_for_devices(void)
1370 {
1371 	int i;
1372 
1373 	for (i = 0; i < DEVICE_WAIT_MAX; i++) {
1374 		struct net_device *dev;
1375 		int found = 0;
1376 
1377 		rtnl_lock();
1378 		for_each_netdev(&init_net, dev) {
1379 			if (ic_is_init_dev(dev)) {
1380 				found = 1;
1381 				break;
1382 			}
1383 		}
1384 		rtnl_unlock();
1385 		if (found)
1386 			return 0;
1387 		ssleep(1);
1388 	}
1389 	return -ENODEV;
1390 }
1391 
1392 /*
1393  *	IP Autoconfig dispatcher.
1394  */
1395 
1396 static int __init ip_auto_config(void)
1397 {
1398 	__be32 addr;
1399 #ifdef IPCONFIG_DYNAMIC
1400 	int retries = CONF_OPEN_RETRIES;
1401 #endif
1402 	int err;
1403 	unsigned int i;
1404 
1405 #ifdef CONFIG_PROC_FS
1406 	proc_create("pnp", S_IRUGO, init_net.proc_net, &pnp_seq_fops);
1407 #endif /* CONFIG_PROC_FS */
1408 
1409 	if (!ic_enable)
1410 		return 0;
1411 
1412 	pr_debug("IP-Config: Entered.\n");
1413 #ifdef IPCONFIG_DYNAMIC
1414  try_try_again:
1415 #endif
1416 	/* Wait for devices to appear */
1417 	err = wait_for_devices();
1418 	if (err)
1419 		return err;
1420 
1421 	/* Setup all network devices */
1422 	err = ic_open_devs();
1423 	if (err)
1424 		return err;
1425 
1426 	/* Give drivers a chance to settle */
1427 	msleep(CONF_POST_OPEN);
1428 
1429 	/*
1430 	 * If the config information is insufficient (e.g., our IP address or
1431 	 * IP address of the boot server is missing or we have multiple network
1432 	 * interfaces and no default was set), use BOOTP or RARP to get the
1433 	 * missing values.
1434 	 */
1435 	if (ic_myaddr == NONE ||
1436 #ifdef CONFIG_ROOT_NFS
1437 	    (root_server_addr == NONE &&
1438 	     ic_servaddr == NONE &&
1439 	     ROOT_DEV == Root_NFS) ||
1440 #endif
1441 	    ic_first_dev->next) {
1442 #ifdef IPCONFIG_DYNAMIC
1443 		if (ic_dynamic() < 0) {
1444 			ic_close_devs();
1445 
1446 			/*
1447 			 * I don't know why, but sometimes the
1448 			 * eepro100 driver (at least) gets upset and
1449 			 * doesn't work the first time it's opened.
1450 			 * But then if you close it and reopen it, it
1451 			 * works just fine.  So we need to try that at
1452 			 * least once before giving up.
1453 			 *
1454 			 * Also, if the root will be NFS-mounted, we
1455 			 * have nowhere to go if DHCP fails.  So we
1456 			 * just have to keep trying forever.
1457 			 *
1458 			 * 				-- Chip
1459 			 */
1460 #ifdef CONFIG_ROOT_NFS
1461 			if (ROOT_DEV ==  Root_NFS) {
1462 				pr_err("IP-Config: Retrying forever (NFS root)...\n");
1463 				goto try_try_again;
1464 			}
1465 #endif
1466 
1467 			if (--retries) {
1468 				pr_err("IP-Config: Reopening network devices...\n");
1469 				goto try_try_again;
1470 			}
1471 
1472 			/* Oh, well.  At least we tried. */
1473 			pr_err("IP-Config: Auto-configuration of network failed\n");
1474 			return -1;
1475 		}
1476 #else /* !DYNAMIC */
1477 		pr_err("IP-Config: Incomplete network configuration information\n");
1478 		ic_close_devs();
1479 		return -1;
1480 #endif /* IPCONFIG_DYNAMIC */
1481 	} else {
1482 		/* Device selected manually or only one device -> use it */
1483 		ic_dev = ic_first_dev;
1484 	}
1485 
1486 	addr = root_nfs_parse_addr(root_server_path);
1487 	if (root_server_addr == NONE)
1488 		root_server_addr = addr;
1489 
1490 	/*
1491 	 * Use defaults wherever applicable.
1492 	 */
1493 	if (ic_defaults() < 0)
1494 		return -1;
1495 
1496 	/*
1497 	 * Record which protocol was actually used.
1498 	 */
1499 #ifdef IPCONFIG_DYNAMIC
1500 	ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1501 #endif
1502 
1503 #ifndef IPCONFIG_SILENT
1504 	/*
1505 	 * Clue in the operator.
1506 	 */
1507 	pr_info("IP-Config: Complete:\n");
1508 
1509 	pr_info("     device=%s, hwaddr=%*phC, ipaddr=%pI4, mask=%pI4, gw=%pI4\n",
1510 		ic_dev->dev->name, ic_dev->dev->addr_len, ic_dev->dev->dev_addr,
1511 		&ic_myaddr, &ic_netmask, &ic_gateway);
1512 	pr_info("     host=%s, domain=%s, nis-domain=%s\n",
1513 		utsname()->nodename, ic_domain, utsname()->domainname);
1514 	pr_info("     bootserver=%pI4, rootserver=%pI4, rootpath=%s",
1515 		&ic_servaddr, &root_server_addr, root_server_path);
1516 	if (ic_dev_mtu)
1517 		pr_cont(", mtu=%d", ic_dev_mtu);
1518 	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
1519 		if (ic_nameservers[i] != NONE) {
1520 			pr_cont("     nameserver%u=%pI4",
1521 				i, &ic_nameservers[i]);
1522 			break;
1523 		}
1524 	for (i++; i < CONF_NAMESERVERS_MAX; i++)
1525 		if (ic_nameservers[i] != NONE)
1526 			pr_cont(", nameserver%u=%pI4", i, &ic_nameservers[i]);
1527 	pr_cont("\n");
1528 #endif /* !SILENT */
1529 
1530 	/*
1531 	 * Close all network devices except the device we've
1532 	 * autoconfigured and set up routes.
1533 	 */
1534 	if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1535 		err = -1;
1536 	else
1537 		err = 0;
1538 
1539 	ic_close_devs();
1540 
1541 	return err;
1542 }
1543 
1544 late_initcall(ip_auto_config);
1545 
1546 
1547 /*
1548  *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1549  *  command line parameter.  See Documentation/filesystems/nfs/nfsroot.txt.
1550  */
1551 static int __init ic_proto_name(char *name)
1552 {
1553 	if (!strcmp(name, "on") || !strcmp(name, "any")) {
1554 		return 1;
1555 	}
1556 	if (!strcmp(name, "off") || !strcmp(name, "none")) {
1557 		return 0;
1558 	}
1559 #ifdef CONFIG_IP_PNP_DHCP
1560 	else if (!strncmp(name, "dhcp", 4)) {
1561 		char *client_id;
1562 
1563 		ic_proto_enabled &= ~IC_RARP;
1564 		client_id = strstr(name, "dhcp,");
1565 		if (client_id) {
1566 			char *v;
1567 
1568 			client_id = client_id + 5;
1569 			v = strchr(client_id, ',');
1570 			if (!v)
1571 				return 1;
1572 			*v = 0;
1573 			if (kstrtou8(client_id, 0, dhcp_client_identifier))
1574 				pr_debug("DHCP: Invalid client identifier type\n");
1575 			strncpy(dhcp_client_identifier + 1, v + 1, 251);
1576 			*v = ',';
1577 		}
1578 		return 1;
1579 	}
1580 #endif
1581 #ifdef CONFIG_IP_PNP_BOOTP
1582 	else if (!strcmp(name, "bootp")) {
1583 		ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1584 		return 1;
1585 	}
1586 #endif
1587 #ifdef CONFIG_IP_PNP_RARP
1588 	else if (!strcmp(name, "rarp")) {
1589 		ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1590 		return 1;
1591 	}
1592 #endif
1593 #ifdef IPCONFIG_DYNAMIC
1594 	else if (!strcmp(name, "both")) {
1595 		ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1596 		return 1;
1597 	}
1598 #endif
1599 	return 0;
1600 }
1601 
1602 static int __init ip_auto_config_setup(char *addrs)
1603 {
1604 	char *cp, *ip, *dp;
1605 	int num = 0;
1606 
1607 	ic_set_manually = 1;
1608 	ic_enable = 1;
1609 
1610 	/*
1611 	 * If any dhcp, bootp etc options are set, leave autoconfig on
1612 	 * and skip the below static IP processing.
1613 	 */
1614 	if (ic_proto_name(addrs))
1615 		return 1;
1616 
1617 	/* If no static IP is given, turn off autoconfig and bail.  */
1618 	if (*addrs == 0 ||
1619 	    strcmp(addrs, "off") == 0 ||
1620 	    strcmp(addrs, "none") == 0) {
1621 		ic_enable = 0;
1622 		return 1;
1623 	}
1624 
1625 	ic_nameservers_predef();
1626 
1627 	/* Parse string for static IP assignment.  */
1628 	ip = addrs;
1629 	while (ip && *ip) {
1630 		if ((cp = strchr(ip, ':')))
1631 			*cp++ = '\0';
1632 		if (strlen(ip) > 0) {
1633 			pr_debug("IP-Config: Parameter #%d: `%s'\n", num, ip);
1634 			switch (num) {
1635 			case 0:
1636 				if ((ic_myaddr = in_aton(ip)) == ANY)
1637 					ic_myaddr = NONE;
1638 				break;
1639 			case 1:
1640 				if ((ic_servaddr = in_aton(ip)) == ANY)
1641 					ic_servaddr = NONE;
1642 				break;
1643 			case 2:
1644 				if ((ic_gateway = in_aton(ip)) == ANY)
1645 					ic_gateway = NONE;
1646 				break;
1647 			case 3:
1648 				if ((ic_netmask = in_aton(ip)) == ANY)
1649 					ic_netmask = NONE;
1650 				break;
1651 			case 4:
1652 				if ((dp = strchr(ip, '.'))) {
1653 					*dp++ = '\0';
1654 					strlcpy(utsname()->domainname, dp,
1655 						sizeof(utsname()->domainname));
1656 				}
1657 				strlcpy(utsname()->nodename, ip,
1658 					sizeof(utsname()->nodename));
1659 				ic_host_name_set = 1;
1660 				break;
1661 			case 5:
1662 				strlcpy(user_dev_name, ip, sizeof(user_dev_name));
1663 				break;
1664 			case 6:
1665 				if (ic_proto_name(ip) == 0 &&
1666 				    ic_myaddr == NONE) {
1667 					ic_enable = 0;
1668 				}
1669 				break;
1670 			case 7:
1671 				if (CONF_NAMESERVERS_MAX >= 1) {
1672 					ic_nameservers[0] = in_aton(ip);
1673 					if (ic_nameservers[0] == ANY)
1674 						ic_nameservers[0] = NONE;
1675 				}
1676 				break;
1677 			case 8:
1678 				if (CONF_NAMESERVERS_MAX >= 2) {
1679 					ic_nameservers[1] = in_aton(ip);
1680 					if (ic_nameservers[1] == ANY)
1681 						ic_nameservers[1] = NONE;
1682 				}
1683 				break;
1684 			}
1685 		}
1686 		ip = cp;
1687 		num++;
1688 	}
1689 
1690 	return 1;
1691 }
1692 __setup("ip=", ip_auto_config_setup);
1693 
1694 static int __init nfsaddrs_config_setup(char *addrs)
1695 {
1696 	return ip_auto_config_setup(addrs);
1697 }
1698 __setup("nfsaddrs=", nfsaddrs_config_setup);
1699 
1700 static int __init vendor_class_identifier_setup(char *addrs)
1701 {
1702 	if (strlcpy(vendor_class_identifier, addrs,
1703 		    sizeof(vendor_class_identifier))
1704 	    >= sizeof(vendor_class_identifier))
1705 		pr_warn("DHCP: vendorclass too long, truncated to \"%s\"\n",
1706 			vendor_class_identifier);
1707 	return 1;
1708 }
1709 __setup("dhcpclass=", vendor_class_identifier_setup);
1710